[PATCH v4 2/2] crypto: marvell - Don't break chain for computable last ahash requests
Boris Brezillon
boris.brezillon at free-electrons.com
Fri Oct 14 03:40:19 PDT 2016
On Wed, 5 Oct 2016 09:56:33 +0200
Romain Perier <romain.perier at free-electrons.com> wrote:
> Currently, the driver breaks chain for all kind of hash requests in order to
> don't override intermediate states of partial ahash updates. However, some final
> ahash requests can be directly processed by the engine, and so without
> intermediate state. This is typically the case for most for the HMAC requests
> processed via IPSec.
>
> This commits adds a TDMA descriptor to copy context for these of requests
> into the "op" dma pool, then it allow to chain these requests at the DMA level.
> The 'complete' operation is also updated to retrieve the MAC digest from the
> right location.
>
> Signed-off-by: Romain Perier <romain.perier at free-electrons.com>
Minor comments below, otherwise it looks good.
Acked-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
>
> Changes in v4:
> - Remove the dummy descriptor at the end of the chain, when a TDMA_RESULT
> is present. So, we re-wrote a bit the code of ahash_complete accordingly.
>
> Changes in v3:
> - Copy the whole context back to RAM and not just the digest. Also
> fixed a rebase issue ^^ (whoops)
>
> Changes in v2:
> - Replaced BUG_ON by an error
> - Add a variable "break_chain", with "type" to break the chain
>
> drivers/crypto/marvell/hash.c | 65 ++++++++++++++++++++++++++++++++-----------
> 1 file changed, 49 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c
> index 9f28468..2a92605 100644
> --- a/drivers/crypto/marvell/hash.c
> +++ b/drivers/crypto/marvell/hash.c
> @@ -312,24 +312,40 @@ static void mv_cesa_ahash_complete(struct crypto_async_request *req)
> int i;
>
> digsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(ahashreq));
> - for (i = 0; i < digsize / 4; i++)
> - creq->state[i] = readl_relaxed(engine->regs + CESA_IVDIG(i));
>
> - if (creq->last_req) {
> + if (mv_cesa_req_get_type(&creq->base) == CESA_DMA_REQ &&
> + (creq->base.chain.last->flags & CESA_TDMA_TYPE_MSK) == CESA_TDMA_RESULT) {
Maybe it's time to create an helper to extract the TDMA desc type (as
you did for the CESA req type with mv_cesa_req_get_type()).
> + __le32 *data = NULL;
> +
> /*
> - * Hardware's MD5 digest is in little endian format, but
> - * SHA in big endian format
> + * Result is already in the correct endianess when the SA is
> + * used
> */
> - if (creq->algo_le) {
> - __le32 *result = (void *)ahashreq->result;
> + data = creq->base.chain.last->op->ctx.hash.hash;
> + for (i = 0; i < digsize / 4; i++)
> + creq->state[i] = cpu_to_le32(data[i]);
>
> - for (i = 0; i < digsize / 4; i++)
> - result[i] = cpu_to_le32(creq->state[i]);
> - } else {
> - __be32 *result = (void *)ahashreq->result;
> + memcpy(ahashreq->result, data, digsize);
> + } else {
> + for (i = 0; i < digsize / 4; i++)
> + creq->state[i] = readl_relaxed(engine->regs +
> + CESA_IVDIG(i));
> + if (creq->last_req) {
> + /*
> + * Hardware's MD5 digest is in little endian format, but
> + * SHA in big endian format
> + */
> + if (creq->algo_le) {
> + __le32 *result = (void *)ahashreq->result;
> +
> + for (i = 0; i < digsize / 4; i++)
> + result[i] = cpu_to_le32(creq->state[i]);
> + } else {
> + __be32 *result = (void *)ahashreq->result;
>
> - for (i = 0; i < digsize / 4; i++)
> - result[i] = cpu_to_be32(creq->state[i]);
> + for (i = 0; i < digsize / 4; i++)
> + result[i] = cpu_to_be32(creq->state[i]);
> + }
> }
> }
>
> @@ -504,6 +520,12 @@ mv_cesa_ahash_dma_last_req(struct mv_cesa_tdma_chain *chain,
> CESA_SA_DESC_CFG_LAST_FRAG,
> CESA_SA_DESC_CFG_FRAG_MSK);
>
> + ret = mv_cesa_dma_add_result_op(chain,
> + CESA_SA_CFG_SRAM_OFFSET,
> + CESA_SA_DATA_SRAM_OFFSET,
> + CESA_TDMA_SRC_IN_SRAM, flags);
> + if (ret)
> + return ERR_PTR(-ENOMEM);
> return op;
> }
>
> @@ -564,6 +586,7 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
> struct mv_cesa_op_ctx *op = NULL;
> unsigned int frag_len;
> int ret;
> + u32 type;
>
> basereq->chain.first = NULL;
> basereq->chain.last = NULL;
> @@ -635,7 +658,15 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
> goto err_free_tdma;
> }
>
> - if (op) {
> + /*
> + * If results are copied via DMA, this means that this
> + * request can be directly processed by the engine,
> + * without partial updates. So we can chain it at the
> + * DMA level with other requests.
> + */
Can you move this comment where it really belongs: when you
conditionally set the CESA_TDMA_BREAK_CHAIN flag.
> + type = basereq->chain.last->flags & CESA_TDMA_TYPE_MSK;
> +
> + if (op && type != CESA_TDMA_RESULT) {
> /* Add dummy desc to wait for crypto operation end */
> ret = mv_cesa_dma_add_dummy_end(&basereq->chain, flags);
> if (ret)
> @@ -648,8 +679,10 @@ static int mv_cesa_ahash_dma_req_init(struct ahash_request *req)
> else
> creq->cache_ptr = 0;
>
> - basereq->chain.last->flags |= (CESA_TDMA_END_OF_REQ |
> - CESA_TDMA_BREAK_CHAIN);
> + basereq->chain.last->flags |= CESA_TDMA_END_OF_REQ;
> +
> + if (type != CESA_TDMA_RESULT)
> + basereq->chain.last->flags |= CESA_TDMA_BREAK_CHAIN;
>
> return 0;
>
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